/sci/ - Science & Math

[Anonymous No.2452501]

Okay /sci/, I need some help with Physics. I've been trying to do it for awhile and can't figure it out. It's projectile motion.

-An object is thrown from the top of a tower that is 115 meters high. The initial horizontal speed of the objects is 5.70 m/s and there is no initial vertical component of speed.

a) What is the velocity of the object at t=2.50 sec?
b) What is the displacement of the object at t=3 seconds?
c) How far from the base of the tower will the object land?

For A, I took acceleration, which in this case is -9.8 since the object is traveling down. Now I took the -9.8 and multiplied it by the 2.50 to get an answer of -24.5. Then I added the 5.7 to get -18.8, which I thought was the answer it the answer key says it is 25.

Help?

[Anonymous No.2452513]

vector addition mang

[Anonymous No.2452541]

>>2452513

That really has nothing to do with this.

[Anonymous No.2452542]

okay look, when you've got two dimensions, and two dimensions only, break it up into X and Y components. What is the initial velocity of the object in the X direction and what is the initial velocity in the Y direction.

Look at these two numbers

Look at the X one

IT NEVER CHANGES- the object will continue to move with that same x component unless some force acts on it, I am assuming you are ignoring air resistance.

now look at the Y one.

IT DOES CHANGE- the object will accelerate in this direction, it will INCREASE, but NEGATIVELY, because acceleration is DOWN

so you can effectively calculate each component and its related shit individually for example: at t = 2.5 seconds.

What is the x velocity? OH IT'S THE SAME AS THE INITIAL LOL

What is the y velocity? OH IT'S JUST v = at

now take those two components and do the magical Pythagorean theorem on 'em

sage for homework

[Anonymous No.2452545]

>>2452541


>>2452542 here

this problem has everything to do with vector addition